DETECTION OF RHODAMINE VIA SURFACE ENHANCED RAMAN SPECTROSCOPY UTILISING AG NANOWIRES

Abstract

Rhodamine, which is extensively used as a synthetic dye in food industry, is regarded as an illegal additive by European Food Safety Authority because of its carcinogenic and toxicological properties. Since it’s a colourless material at low concentrations such as 10-7 M, its detection via spectroscopical methods is very challenging and crucial in terms of food safety issues. Surface Enhanced Raman Spectroscopy (SERS) provides a fast and cheap method for detection of such molecules at ultra-low concentrations. It is based on the principle of boosting Raman signals, which have low intensity by nature, by utilising metal nanoparticles in order to enhance Raman signals by creating hot-spots. In this study Ag nanowires were synthesized, their crystal structure is characterized via XRD analysis, their surface morphology and radius are determined via SEM images and EDS analysis was performed for determining their chemical composition. Afterwards, rhodamine solutions which were prepared at 10-4 – 10-7 M was dropcasted onto Ag nanowire solutions. After selecting three characteristic Raman peaks belonging to the Rhodamine molecule, which are located at 612, 1189 and 1362 cm-1, detection of Rhodamine was performed at these ultra low concentrations. As a result, one can conclude that, Ag nanowires can be utilized as possible SERS substrates for detection of Rhodamine at low concentrations by exhibiting significant reproducibility, stability and recyclability.